Evidence for Quantization from the Electric Polarization of Acetic Acid Vapor

The dielectric constant of acetic acid vapor was measured at various pressures and temperatures. The results indicate a departure from Debye's theory which suggests an internal transition, with respect to temperature variation, from one type of single molecule to another. Near saturation there was detected a small amount of association of a kind increasing the molecular polarization. The anomaly is discussed from the point of view of the new quantum mechanics and it is suggested as an explanation that the effect is due to a transition from one state to a higher state of vibration associated with the OH group. The data are interpreted in terms of the proposed extension of Van Vleck's theory given in the following note. The Raman frequencies given by Dadieu and Kohlrausch indicate that the fundamental vibration frequency due to the OH group is of such a value as to produce transitions of quantum state in precisely the observed region of temperature. This is in agreement with the proposed theory, particularly since molecular polarization measurements in general indicate that the OH group always has associated with it a large electric moment.The electric moment of the acetic acid molecule cannot be calculated accurately but the data indicate roughly a transition from 1.4×{}10^-18 in the ground state to an average value greater than 1.7×{}10^-18 c.g.s. e.s.u. in the upper states.A discussion is given of the anomalous behavior of other physical properties of the vapor, regarding it as a statistical distribution of molecules, surrounded by different force fields associated with the change in electric moment. The possibility of attributing previously observed discrepancies between refractivities and the optical parts of the dielectric polarization to the above mentioned type of quantization is suggested.